Dec 18, 2012

Hospitalization increases the risk of dementia. What events during a hospitalization are associated with a subsequent dementia diagnosis in the elderly?

Alzheimer's Reading Room

Older people often worry about dementia.

New research published in BioMed Central's open access journal Critical Care looked at illness requiring hospitalization and treatment in the intensive care units (ICU).

The study found that infection or severe sepsis, neurological dysfunction, such as delirium, or acute dialysis are all independently associated with an increased risk of a subsequent diagnosis of dementia.

Subscribe to the Alzheimer's Reading Room

Email:

Methodology

A cohort study of a random 5% sample of Medicare beneficiaries who received intensive care in 2005 and survived to hospital discharge, with three years of follow-up (through 2008) was conducted using Medicare claims files.

The researchers defined dementia using the International Classification of Diseases, 9th edition, clinical modification (ICD-9-CM) codes and excluded patients with any prior diagnosis of dementia or cognitive impairment in the year prior to admission.

They used an extended Cox model to examine the association between diagnoses and events associated with the critical illness and a subsequent diagnosis of dementia, adjusting for known risk factors for dementia.

Results

Over the three years of follow-up, dementia was newly diagnosed in 4,519 (17.8%) of 25,368 patients who received intensive care and survived to hospital discharge.

After accounting for known risk factors, having an infection (adjusted hazard ratio (AHR) =1.25; 95% CI, 1.17 to 1.35), or a diagnosis of severe sepsis (AHR=1.40; 95% CI, 1.28 to 1.53), acute neurologic dysfunction (AHR= 2.06; 95% CI, 1.72 to 2.46), and acute dialysis (AHR=1.70; 95% CI, 1.30 to 2.23) were all independently associated with a subsequent diagnosis of dementia.

No other measured ICU factors, such as need for mechanical ventilation, were independently associated.

Conclusions

Among ICU events, infection or severe sepsis, neurologic dysfunction, and acute dialysis were independently associated with a subsequent diagnosis of dementia.

Patient prognostication, as well as future research into post-ICU cognitive decline, should focus on these higher-risk subgroups.

Bob DeMarco is the Founder of the Alzheimer's Reading Room and an Alzheimer's caregiver. The ARR knowledge base contains more than 3,811 articles with more than 306,100 links on the Internet. Bob lives in Delray Beach, FL.

The Alzheimer's Reading Room does not provide medical advice. The contents are for informational purposes only, and are not intended to substitute for professional medical advice, diagnosis or treatment. The views of the individuals that write on this website, contribute articles, or are quoted on this site are not necessarily those of the Alzheimer's Reading Room. For specific, personalized medical advice we encourage you to contact your physician.Unauthorized use and/or duplication of all materials and articles in the Alzheimer's Reading Room without the express and written permission from Bob DeMarco are strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given and appropriate and specific direction to the original content is included.